1. Field of the Invention
The present invention relates to current control circuits and motor drive circuits, and more particularly, to a current control circuit and a motor drive circuit that can control a drive current in accordance with an input control signal.
2. Description of the Related Art
Conventionally, a motor drive circuit is known that controls a drive current for a motor by: driving a current mirror circuit in accordance with an external control signal; separately generating a source control current and a sink control current by the current mirror circuit; controlling a source drive circuit of the motor by the source control current generated by the current mirror circuit; and controlling a sink drive circuit by the sink control current generated by the current mirror circuit (refer to Japanese Laid-Open Patent Application No. 60-237871, for example).
The conventional motor drive circuit separately generates the source control current and the sink control current by the current mirror circuit, and controls the source drive circuit of the motor by the source control current generated by the current mirror circuit. Hence, there is a problem in that the drive current for the motor is varied when the characteristics of a transistor supplying a current to the source of the current mirror circuit and those of a transistor supplying a current to the sink of the current mirror circuit do not match.
In addition, in the conventional motor drive circuit, the configuration of the source drive circuit and that of the sink drive circuit are different. For this reason, the characteristics of the source side and those of the sink side do not match, which results in variation of the drive current for the motor.